Abstract: A method of ultra-high aspect ratio high resolution vertical directionality controlled metal-assisted chemical etching, V-MACE, is provided that includes forming a pattern on a substrate surface, using a lithographic or non-lithographic process, forming hole concentration balancing structures on the substrate, using a lithographic process or non-lithographic process, where the concentration balancing structures are proximal to the pattern, forming mechanical anchors internal or external to the patterned structures, forming pathways for etchant and byproducts to diffuse, and etching vertical features from the substrate surface into the substrate, using metal-assisted chemical etching, MACE, where the vertical features are confined to a vertical direction by the concentration balancing structures.